In Case Control Study, Two-Thirds of Patients With Severe Depression Had Underlying Metabolic Abnormalities
A recent study suggests that potentially treatable metabolic abnormalities in the central nervous system may underlie a large proportion of cases of severe, treatment-resistant depression. These abnormalities, such as folate deficiency in the cerebrospinal fluid, are not screened for regularly, as they require a spinal tap to diagnose.
Researchers led by Lisa A. Pan were inspired to assess metabolic function in people with treatment-resistant depression after a young patient with severe, persistent depression who had attempted suicide several times improved dramatically after being diagnosed with a tetrahydrobiopterin deficiency in his cerebrospinal fluid and treated for the deficiency. Tetrahydrobiopterin is critical to the production of monoamine neurotransmitters.
The researchers carried out a case-control study of 33 teen and young adult patients who had had treatment-resistant depression since childhood and 16 healthy control participants. Twenty-one of the 33 patients with severe depression had metabolic abnormalities in their cerebrospinal fluid. Twelve had cerebral folate deficiencies (but no folate deficiency in blood tests). Those who took folinic acid for at least six weeks (1–2 mg/kg/day) in addition to their regular medications showed sometimes dramatic improvement in their depression.
Other metabolic issues identified in the patients with severe depression included abnormal levels of acylcarnitine in five patients, low tetrahydrobiopterin intermediates in one, low guanidinoacetate in another, and unusual creatine/creatinine ratios in three patients. None of the healthy participants had any metabolic abnormality.
While the study, published in the American Journal of Psychiatry in 2017, was small, it suggests that the underlying causes of some severe depression cases are going undiagnosed and untreated. The authors suggest that assessment of metabolic function should be more common in cases of severe treatment-resistant depression.
Creatine Supplements May Speed Up Response to Escitalopram, Improve Brain Connectivity
Antidepressants can take weeks to begin working, and researchers have been investigating ways to speed up this process. A 2012 study by In Kyoon Lyoo and colleagues in the American Journal of Psychiatry found that among 52 women taking the selective serotonin reuptake inhibitor (SSRI) antidepressant escitalopram (Lexapro) for unipolar depression, those who were prescribed an additional creatine supplement had earlier and greater decreases in depression symptoms than those who received a placebo in addition to the escitalopram.
The difference between the two groups was evident by the second week of treatment. At the end of the 8-week study, 52% of those who received creatine had achieved remission, compared to 26% of those in the placebo group.
Creatine, a supplement sometimes used by weightlifters, increases cellular energy. The women received 3g/day of creatine for the first week of the study, and 5g/day thereafter.
The same research group recently published more data from their creatine study. The new article by Sujung Yoon and colleagues in the journal Biological Psychiatry shows that following the creatine supplementation, the women in the creatine group had greater levels of N-acetylaspartate (a sign of healthy neurons) in their prefrontal cortex and also had greater levels of brain connectivity than women in the placebo group.
